1. FIELD OF THE INVENTION
The present invention relates to a cap unit for a container, especially a container on a tank lorry or similar means of transport and having a cap and a circumferential skirt, in which container the skirt is mounted defining an aperture in the container and which cap is movable between a first position and a second position in which first position the cap covers the aperture and seals it and in which second position the cap at least partly uncovers the aperture, the cap being revolvably journalled around an axis extending perpendicularly to the plane defined by the aperture and being located outside the aperture so that the cap is able to swing in a plan parallel with the plane defined by the aperture between the first position and the second position, and the cap and the skirt having respective claw-shaped catching means which are arranged so as to maintain the cap longitudinally in relation to the skirt and at the same time allow the cap to swing from the first position to the second position around the mentioned pivoting axis.
2. DESCRIPTION OF THE PRIOR ART
Conventional cap units used in tank lorries are mounted on the highest point of the tanker and are provided with a number of screw spindles, typically 3-6 screw spindles per cap, which are to be handled manually in order to allow closing and opening of the cap unit. In a feed tanker or other tank lorry, for instance a tank lorry transporting chemicals, petrol, fuel oil, cement, feed or feedstuff, 4-8 cap units may typically be mounted depending on the size and compartment division of the tank lorry.
When filling fluid or particulate material on the tank lorry the driver in the first place has to get off the driver's cab and climb to the top of the tank lorry, typically in a height of 3-4 meter above the ground, raise the safe handrail which is statutory on tank lorries, open the cap units by releasing the screw spindles of the respective cap units, typically 12-48 screw spindles, remove the safe handrail, dismount the top of the tank lorry, board the driver's cab of the lorry and drive the lorry to the point below the storage silo or another place for filling of fluid or particulate material to the tank lorry.
After filling of material to the tank lorry the same phases of work have to be made after the tank lorry has been driven away from the position below the storage silo, with the only difference that at this stage the screw spindles are not to be released but to be fastened. As is evident, these phases of work are very time-consuming and rather dangerous to the driver who has to climb the top of the tank lorry twice during the filling process and in a substantial height above the ground make a number of manual operations, even in unpleasant weather such as rain, sleet or snow.